Conventionally, there have been proposed a number of catalysts used for purifying exhaust gas from an internal combustion engine of an automobile and others.
These days, most of the catalysts are three-way catalysts that purify HC, CO and NOx at the same time.
As such a three-way catalyst, a two-layer type having an inside layer containing Pd and an outside layer containing Rh is known (see Patent Literature 1).    Patent Literature 1: Unexamined Japanese Patent Publication No. 10-501737
In recent years, control on exhaust emissions from an automobile is tightened, which demands a further reduction of HC, CO, and NOx emissions. However, conventional exhaust gas purifying catalysts cannot always sufficiently comply with the tightened control requirements. In addition, when an amount of noble metals used is increased to improve catalytic performance, a price of the exhaust gas purifying catalyst has to be raised, which is a problem.
The present invention has been made in view of the above circumstances. An object of the present invention is to provide an exhaust gas purifying catalyst which exhibits high catalytic performance and is capable of restraining an amount of noble metals used.